Abstract
We propose a systematic framework to classify (2+1)-dimensional (2+1D) fermionic topological orders without symmetry and 2+1D fermionic/bosonic topological orders with symmetry . The key is to use the so-called symmetric fusion category to describe the symmetry. Here, describing particles in a fermionic product state without symmetry, or describing particles in a fermionic (bosonic) product state with symmetry . Then, topological orders with symmetry are classified by nondegenerate unitary braided fusion categories over , plus their modular extensions and total chiral central charges. This allows us to obtain a list that contains all 2+1D fermionic topological orders without symmetry. For example, we find that, up to fermionic topological orders, there are only four fermionic topological orders with one nontrivial topological excitation: (1) the fractional quantum Hall state, (2) a Fibonacci bosonic topological order stacking with a fermionic product state, (3) the time-reversal conjugate of the previous one, and (4) a fermionic topological order with chiral central charge , whose only topological excitation has non-Abelian statistics with spin and quantum dimension .
- Received 28 August 2015
- Revised 25 July 2016
DOI:https://doi.org/10.1103/PhysRevB.94.155113
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